Sound suppressors on firearms create backpressure that causes some of the propellant gas in the suppressor to flow back into the barrel and gas system after the bullet exits. This contaminates the barrel with solids, and can affect operation of the receiver due to contamination and departure from the design backpressure. Current suppressors maintain high pressures in the bore and gas systems longer than the system was designed to handle. This causes timing issues with the gas system that result in high stresses, accelerated wear, damaged extractors and cases, etc. An entire cottage industry has grown to provide adjustable gas blocks to address these shortcomings. Shorter barrels may be more affected. For example a suppressor that works on a 20-inch barrel may impair the repeating mechanism of a rifle with 14.5-inch barrel. Therefore, a need exist for an effective sound suppressor with reduced back pressure. Current suppressors cause high backpressure because they try to contain the blast, preventing it from flowing through the suppressor. They only absorb a small percentage of gas volume before the gas compresses and flow ceases. Another disadvantage of prior suppressors is that they make the gun longer by extending forward of the barrel.